JP3393175B2 - Paper feeder for printing press - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device of a printing machine capable of detecting the overlapped feeding of two or more sheets when the sheets are conveyed along a conveying path.

[0002]

2. Description of the Related Art For example, in a paper feeding mechanism equipped in a printing machine, stacked sheets are separated and conveyed one by one from the top, but when passing through a printing drum, two or more sheets are overlapped. May be transported. In order to detect the overlapped feeding of the sheets with high accuracy, it is general to sample a wide range of the sheet to be fed.

FIG. 19 is a diagram in which a light transmission type detection sensor is installed in the paper feeding mechanism. The detection sensor 1 includes a light emission sensor 1a and a light emission sensor 1a sandwiching a sheet to be detected.
It is constituted by the light receiving sensor 1b arranged to face. Paper 1
1 is located between the light emitting sensor 1a and the light receiving sensor 1b,
It is better to be perpendicular to the line connecting the light emitting sensor 1a and the light receiving sensor 1b. Thereby, at the time of detection by the detection sensor 1,
It is possible to reduce the change in transmittance due to the influence of reflected light.

In the above structure, when the overlapped feeding of the paper 11 is detected, there is a paper range which is not suitable for the sample. FIG. 20 shows the registration roller 9 at the beginning of paper feeding in FIG.
Indicates that the paper 11 is slackened. Figure 20
In the state shown in (1), the paper 11 may not be positioned in the middle of the light emitting sensor 1a and the light receiving sensor 1b, and may not be perpendicular to the line connecting the light emitting sensor 1a and the light receiving sensor 1b. Further, FIG. 21 shows a state in which the paper 11 is separated from the pickup roller 8 at the end of the paper feeding in FIG. Even in this state, the same problem as in the beginning of the sheet feeding in FIG. 20 occurs.

As described above, the leading end and the trailing end of the sheet 11 in the conveying direction are not suitable for the sample for the overlap feeding detection because the state with respect to the detection sensor 1 is unstable. Will be less accurate.

By the way, in order to use only the middle of the paper to be passed as a sample for the overlap feeding detection, the paper size becomes important. FIG. 22 shows that the paper feeding mechanism of FIG.
The timing of the light receiving sensor 1b when paper is passed is shown.

If A5 paper is sampled in the sample range of A3 paper, a range without paper is sampled.
On the other hand, when A3 paper is sampled in the sample range of A5 paper, the sampleable range is not used.

[0008]

SUMMARY OF THE INVENTION The present invention solves these problems, determines the optimum sample range according to the paper size, and is capable of accurately detecting overlapped feeding of paper. The purpose is to provide a paper device.

[0009]

In order to achieve the above object, the invention of claim 1 is a pickup roller which separates and conveys the sheets placed on a placing table one by one, and is fed from the pickup roller. Receiving incoming paper,
In a paper feeding device of a printing machine including a pair of registration rollers that conveys the paper to the printing unit side at a predetermined timing after temporarily stopping the conveyance and slackening the paper, the paper is conveyed between the pickup roller and the pair of registration rollers. Output a signal according to the thickness of the paper once slackened,
The paper thickness detecting means provided on the conveyance between the pickup roller and the pair of registration rollers, the paper size detecting means for detecting the paper size of the conveyed paper in the conveying direction, and the paper size detecting means. A detection range excluding the leading edge and the trailing edge of the sheet is set according to the detected sheet size, and the sheets are superposed based on the sample data detected by the sheet thickness detecting means in the set detection range. And a processing unit for determining the presence or absence of feeding.

According to a second aspect of the present invention, in the sheet feeding device of the printing machine according to the first aspect, the sheet size detecting means is a signal according to the sheet size in the sheet conveying direction based on switching of the switch on the operation panel. Is output.

According to a third aspect of the present invention, in the sheet feeding device of the printing machine according to the first aspect, the sheet size detecting means is provided in a storing means for storing a sheet to be conveyed, and a conveying direction of the accommodated sheet. It is characterized in that it outputs a signal according to the paper size.

According to a fourth aspect of the present invention, in the sheet feeding device of the printing machine according to the first aspect, the processing unit determines the sheet size in the transport direction based on the sample data detected by the sheet thickness detection unit, and makes the determination. It is characterized in that the detection range of the paper thickness detecting means is varied according to the selected paper size.

According to a fifth aspect of the present invention, in the sheet feeding device of the printing machine according to the first aspect, the processing means includes sample data detected by the paper thickness detecting means in the detection range of the sheet conveyed this time, It is characterized in that the presence / absence of the overlapped feeding of the paper is determined by comparison with sample data detected by the paper thickness detecting means in the detection range of the paper conveyed before the paper.

According to a sixth aspect of the invention, in the sheet feeding device of the printing machine according to the first aspect, the sheet thickness detecting means is a transmitted light type sensor.

According to a seventh aspect of the invention, in the sheet feeding device of the printing machine according to the first aspect, the sheet thickness detecting means is a reflected light type sensor.

According to an eighth aspect of the invention, in the sheet feeding device of the printing machine according to the first aspect, the sheet thickness detecting means is an ultrasonic sensor.

According to a ninth aspect of the invention, in the sheet feeding device of the printing machine according to the first aspect, the sheet thickness detecting means is a contact type sensor.

[0018]

According to the present invention, a means for detecting the paper size in the carrying direction or a means for designating the paper size in the carrying direction is provided, and the sample range of the paper to be carried is determined based on such information. Therefore, if the paper is a standard size, an optimum sample range can be obtained, and highly accurate overlap feed detection can be performed.

Further, during printing (sheet passing), a plurality of points in the sheet passing direction are sampled, the sheet size in the sheet passing direction is calculated from the sampled data, and the instability before and after the sheet is determined from the calculated sheet size. Since the range excluding the area is used as the overlap feed detection data, an optimum sample range that matches the paper size can be obtained, and highly accurate overlap feed detection can be performed.

The paper thickness detecting means used at that time may be any of a transmission type or reflection type optical sensor, an ultrasonic type sensor and a contact type sensor. When an optical sensor is used, it can be easily calculated by storing the unconveyed light receiving level and using it when calculating the sheet size in the conveying direction.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) FIG. 1 is a block diagram showing a first embodiment of a stacking feed detecting device relating to a sheet feeding device of a printing machine according to the present invention, and FIG.
FIG. 3 is a diagram showing an operation panel of the embodiment, and FIG. 3 is a diagram showing an arrangement configuration of motors of a sheet feeding device of a printing machine according to the present invention.

The overlapped feeding detecting device relating to the paper feeding device of the printing machine according to the first embodiment is composed of a paper thickness detecting means 1, an amplifying circuit 2, an operation panel 3, a microcomputer 4, a driving circuit 5, a carrying motor 6, The encoder sensor 7 is provided.

The paper thickness detecting means 1 is composed of a transmissive optical sensor having a light emitting sensor 1a and a light receiving sensor 1b. The light emitting sensor 1a is composed of, for example, a light emitting diode, a laser diode, a lamp, or the like. As shown in FIG. 3, the light emission sensor 1a is arranged at a predetermined distance L1 above the conveying path 10 between the pickup roller 8 and the registration roller 9 which is inclined upward to the right.

The light receiving sensor 1b is composed of, for example, a photodiode. As shown in FIG. 3, the light receiving sensor 1b
Is disposed below the transport path 10 at a predetermined distance L2 (= L1) and faces the light emitting sensor 1a.

The light emitted from the light emitting sensor 1a is directly received by the light receiving sensor 1b unless the paper 11 is conveyed.
Will be received by. On the other hand, when the paper 11 is being conveyed, the light passing through the paper 11 is received by the light receiving sensor 1b. The light received by the light receiving sensor 1b is input to the amplifier circuit 2 after being converted into an electric signal according to the amount of received light.

The amplifier circuit 2 amplifies an electric signal input from the light receiving sensor 1b of the paper thickness detecting means 1 with a predetermined amplification factor and inputs the amplified signal to the microcomputer 4.

The operation panel 3 is provided with an operation key 12, a paper size lamp 13, a double-sheet feeding warning lamp 14, and a ten-key for setting the number of printed sheets. The operation keys 12 are selected and operated by the user, and include a start key 12a for designating the start of printing, a stop key 12b for designating the stop of printing, and paper sizes (A3, B4, A4, B5, A).
A paper size key 12c for designating (5, irregular type) is provided.

The paper size lamp 13 is instructed by the microcomputer 4 in accordance with the paper size, that is, A3 lamp 13a, B4 lamp 13b, A4 lamp 13c, B.
5 lamp 13d, A5 lamp 13e, irregular lamp 13
Any of f lights up.

The double-sheet feeding warning lamp 14 is turned on by a command from the microcomputer 4 when it is determined that the double-sheet feeding is performed.

The microcomputer 4 comprises a one-chip microcomputer having an A / D converter 15, a CPU 16 as a processing means, a ROM 17 and a RAM 18 as a storage means.

The A / D converter 15 converts the signal input from the amplifier circuit 2 into a digital signal corresponding to its analog value and inputs the digital signal to the CPU 16.

The CPU 16 is composed of a microprocessor or the like, and based on the information from the operation panel 3, the signal from the amplifier circuit 2, and the signal from the encoder sensor 7, the paper 1
1 carrying control, paper size determination, paper size display switching, sample range setting, stack feed detection of paper 11, and the like.

To further explain, the CPU 16 determines the paper size based on the paper size information selected by the paper size key 12c of the operation panel 3, lights the paper size lamp 13 according to the paper size, and detects the paper thickness. The sample range of 1 is set.

The CPU 16 samples the digital signal input from the A / D converter 15 at the input timing of the interrupt signal from the encoder sensor 7 within the set sampling range.

The CPU 16 determines the presence / absence of the overlap feeding of the paper 11 based on the sample data based on the signal of the paper thickness detecting means 1, and controls the overlap feeding warning lamp 14 to be turned on / off based on the result of the judgment.

The CPU 16 outputs to the drive circuit 5 a command for driving and stopping the conveying motor 6 based on the operation signals of the start key 12a and the stop key 12b of the operation panel 3.

The CPU 16 is internally provided with a paper feed counter, and performs a process of incrementing the count value by one each time an interrupt signal is input from the encoder sensor 7.

The ROM 17 stores a processing program required for the CPU 16 to perform a series of processing, data of a sample range according to the paper size, and the like.

The RAM 18 stores the sample data of the first sheet 11 within the sample range set by the CPU 16, and sequentially stores the sample data of the second and subsequent sheets 11 within the sample range set by the CPU 16. I remember the update. The RAM 18 also stores the count value of the paper feed counter of the CPU 16.

The drive circuit 5 comprises a pickup motor drive circuit 5a and a registration motor drive circuit 5b. The pickup motor drive circuit 5a rotates and stops the pickup motor 6a, which will be described later, based on a command from the CPU 16. Registration motor drive circuit 5b
Rotates and stops a registration motor 6b, which will be described later, based on a command from the CPU 16.

The transporting motor 6 comprises a pickup motor 6a connected to a pickup roller 8 via a drive belt and a registration motor 6b connected to a registration roller 9 via a drive belt. The pickup motor 6a rotationally drives the pickup roller 8 that separates and conveys the sheets 11 of the same quality, which are stacked on a vertically movable sheet feeding table, one by one from the top.

The registration motor 6b rotationally drives the registration roller 9 which is a pair of rollers for taking in the paper 11 separated and sent by the pickup roller 8 and conveying it to the print drum side (not shown).

The encoder sensor 7 is the registration motor 6
A one-shot pulse signal is output when the sheet b rotates by a predetermined length (for example, 1 mm) to be fed. This one-shot pulse signal is input to the CPU 16 of the microcomputer 4 as an interrupt signal.

(Second Embodiment) FIG. 4 is a block diagram showing a second embodiment of a stacking feed detecting device relating to a paper feeding device of a printing machine according to the present invention, and FIG.
FIG. 6 is a diagram showing the operation panel of the embodiment, and FIG. 6 is a diagram showing the configuration of the paper size detecting means of the second embodiment. In addition,
The same components as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

The overlapped feeding detecting device according to the sheet feeding device of the printing machine of the second embodiment has a configuration in which the sheet size key 12c and the sheet size lamp 13 of the operation panel 3 in the configuration of the first embodiment are deleted. is there.

As shown in FIG. 6, a paper size discriminating sensor 20 is provided on the paper feed table 19 on which the paper 11 is stacked. The paper size determination sensor 20 is an A3 paper sensor 20.
a, B4 paper sensor 20b, A4 paper sensor 20c, B
A 5 sheet sensor 20d and an A5 sheet sensor 20e are provided. Each of the sensors 20a to 20e is, for example, a reflected light type sensor integrally including a light emitting sensor and a light receiving sensor,
Whether or not the paper 11 is present on the detection surface is detected, and the paper 1 is detected.
A signal corresponding to the presence or absence of 1 is output.

For example, the sheets 1 stacked on the sheet feed table 19
If 1 is A4 size, A4 paper sensor 20c, B5
Since the paper 11 exists on each of the paper sensor 20d and the A5 paper sensor 20e, the A4 paper sensors 20c and B are provided.
A signal indicating that there is a sheet (for example, a binary signal “1”) is input to the CPU 16 of the microcomputer 4 from the 5-sheet sensor 20d and the A5 sheet sensor 20e. In contrast,
Since the paper 11 does not exist on each sensor of the A3 paper sensor 20a and the B4 paper sensor 20b, the A3 paper sensor 2
0a, B4 paper sensor 20b outputs a signal indicating that there is no paper (for example, a binary signal "0") to the microcomputer 4
Is input to the CPU 16.

In the CPU 16, the paper size discrimination sensor 2
Paper 1 stacked on the paper feed table 19 based on a signal from 0
The size of 1 in the transport direction is determined.

Next, the operation of the overlapped feeding detection apparatus according to the first and second embodiments will be described with reference to the flow charts shown in FIGS. Note that in the flowchart of FIG. 7, processing portions executed only in the first embodiment are surrounded by broken lines, and processing portions executed only in the second embodiment are surrounded by dashed line. Further, the paper feed table 19 can be moved up and down by an elevator function (not shown), and the paper 11 having the same quality is stacked on the paper feed table 19.

Printing is started if the start key 12a is pressed, but only in the first embodiment, the paper size key 12c is displayed before (or in parallel with) confirmation of pressing of the start key 12a.
If the paper size key 12c is pressed (ST1-YES), the paper size display switching operation shown in FIG. 8 is performed (ST2).

In the paper size display switching operation, "A3" is displayed each time the user presses the paper size key 12c.
→ B4 → A4 → B5 → A5 → indeterminate → A3 ”. The paper size lamp 13 for the paper size determined based on the press of the paper size key 12c is turned on.

In the flowchart of FIG. 8, when the paper size key 12c is pressed, the irregular lamp 13f
If is lit (ST3-YES), the paper size is A
3 is determined (ST4), and the A3 lamp 13a is turned on (ST5). If the A3 lamp 13a is on (ST
6-YES), the paper size is determined to be B4 (ST
7), the B4 lamp 13b is turned on (ST8). If the B4 lamp 13b is on (ST9-YES), the paper size is determined to be A4 (ST10), and the A4 lamp 13
c lights up (ST11). If the A4 lamp 13c is turned on (ST12-YES), the paper size is determined to be B5 (ST13), and the B5 lamp 13d is turned on (S).
T14). If the B5 lamp 13d is lit (ST1
5-YES), the paper size is determined to be A5 (ST1
6), the A5 lamp 13e is turned on (ST17). B5
If the lamp 13d is not turned on (ST15-N
O), that is, if the A5 lamp 13e is lit,
The paper size is determined to be an irregular size (ST18), and the irregular size lamp 13f is turned on (ST19).

When the start key 12a is pressed (ST
20-YES), only in the second embodiment, the paper size determination operation of the paper feed tray shown in FIG. 9 is performed (ST21). In the paper feed tray paper size determination operation, the paper size of the paper 11 stacked on the paper feed tray 19 is determined by a signal from the paper size determination sensor 20 shown in FIG.

In the configuration shown in FIG. 6, all the sensors corresponding to the size of the paper 11 loaded on the paper feed table 19 and the sensors of sizes smaller than that are turned on, so that the largest paper (A3) is checked. I do.

In the flowchart of FIG. 9, if the A3 paper sensor 20a is on (ST22-YES),
The paper size is determined to be A3 (ST23). A3 paper sensor 20a is not turned on (ST22-NO), B
4 If the paper sensor 20b is on (ST24-YE
S), and the paper size is determined to be B4 (ST25). B
4 Paper sensor 20b is not turned on (ST24-N
O), if the A4 paper sensor 20c is on (ST2
6-YES), the paper size is determined to be A4 (ST2
7). The A4 paper sensor 20c is not turned on (ST2
6-NO), if the B5 paper sensor 20d is on (ST28-YES), the paper size is determined to be B5 (ST29). If the B5 paper sensor 20d is not on (ST28-NO) and the A5 paper sensor 20e is on (ST30-YES), the paper size is determined to be A5 (ST31). If the A5 paper sensor 20e is off (ST30-NO), the paper size is determined to be an irregular size (ST32).

If the paper size determined by the paper size display switching operation or the paper size determination of the paper feed tray is unfixed before the start of printing (ST33-YES), the overlap feed detection range is determined. Since it is not present, the printing operation in which two sheets are not fed is detected (ST34).

If the paper size is not an irregular size (ST33
-NO), the operation of determining the sample range is performed (ST3
5). In the operation of determining the sample range, the sample range for double-sheet feeding by the paper thickness detecting unit 1 is determined based on the paper size determined by the paper size display switching or the paper size determination on the paper feed tray.

In the flowchart of FIG. 10, if the paper size is determined to be A3 paper (ST36-YES), the sample range is determined to be 120 to 370 mm (ST3).
7). If the paper size is determined to be B4 paper (ST38-
YES), the sample range is determined to be 100 to 314 mm (ST39). If the paper size is determined to be A4 paper (ST40-YES), the sample range is 100 to 247.
mm (ST41). If the paper size is determined to be B5 paper (ST42-YES), the sample range is set to 10
It is determined to be 0 to 207 mm (ST43). If the paper size is not B5 paper (ST42-NO), that is, A5
If it is paper, the sample range is determined to be 100 to 160 mm (ST44).

Although the sample range in this example is basically 100 mm from the leading edge of the sheet to 50 mm at the trailing edge of the sheet, the capacity of the sample data in the RAM 18 and the CPU 16
Due to the calculation processing speed, the limit is set so as not to exceed 250 mm. When the capacity of the sample data in the RAM 18 and the calculation processing speed of the CPU 16 are not particularly problematic, the sample range can be widened. On the contrary, when the capacity of the sample data in the RAM 18 is small and the calculation processing speed of the CPU 16 is slow, the sample range may be narrowed.

In this example, since the range of A3 paper is limited, the sample range of A3 paper is set from 120 mm at the leading edge of the paper to 50 mm at the trailing edge of the paper. Although the limit of 20 mm is added to the front end of the paper, it may be added to the rear end of the paper or may be added separately to the front end and the rear end of the paper.

When the sample range is determined as described above, the operation shifts to the sheet feeding operation and the two-sheet overlap feeding detection printing operation including the two-sheet overlap feeding detection shown in FIGS.

First, if the double-sheet feeding warning lamp 14 is turned on, it is turned off (ST46). Then, the pickup motor 6a is turned on (ST47), and the pickup roller 8 is rotationally driven in the arrow direction of FIG. This allows
The first sheet 11 located at the uppermost part of the paper feed tray 19 is separated from the sheet 11 below it and conveyed.

As shown in FIG. 20, the pickup motor 6a is rotationally driven for 300 ms until the leading edge of the paper 11 hits between the rollers 9a and 9b of the registration roller 9 and slack is formed (ST48), and then stopped. (ST49).

Next, the registration motor 6b is turned on (ST
50), the registration roller 9 is rotationally driven in the direction of the arrow in FIG. As a result, the sheet 11 on which the slack is formed is
It is sent to the printing unit (printing drum) side not shown. In this example, the rotation of the registration roller 9 causes the paper 11
Are all sent to the printing section.

At the timing when the registration motor 6b is turned on (when the rotation starts), the paper feed counter in the CPU 16 is cleared to "0" (ST51). When the count value of the paper feed counter reaches the sampling start value (ST52
-YES), the point where the paper feed counter is cleared
The sample processing in the paper transport direction is performed by the paper thickness detecting means 1 within the sample range determined by the sample range determining operation.

In this sample processing, the light emitted from the light emitting sensor 1a passes through the paper 11 and is received by the light receiving sensor 1b. The received light signal is amplified by the amplifier circuit 2, converted into a digital signal by the A / D converter 15, and taken into the CPU 16. Then, this digital signal is used as sample data by the paper thickness detecting means 1 in the RAM 18
(ST53). Sample data is RAM1
When stored in RAM 8, the count value of the paper feed counter at that time is also stored in RAM 18 (ST54).

In performing the above sample processing, the sample interval of the light receiving sensor 1b is determined by the encoder sensor 7 connected to the registration roller 9. In the encoder sensor 7, the registration roller 9 sets the paper 11 to 1
One pulse is output each time the motor rotates by the amount sent by mm, and this signal causes the CPU 16 to generate an interrupt.

The paper feed counter in the CPU 16 has a RAM every time an interrupt signal is input from the encoder sensor 7.
The count value stored in 18 is incremented by 1 (ST55). Note that the sampling interval may be a fixed time system.

The above sample processing is repeated until the paper feed counter reaches the sample end value. When the paper feed counter reaches the sample end value (ST56-YES),
Paper 11 is further 60 mm (rear edge 50 + margin 10 m
m) Carry it and send it out (ST57). Then, the registration motor 6b is turned off (ST58), and printing is performed (S).
T59).

If the stop key 12b is pressed after printing (ST60-YES), the initial state is restored.
On the other hand, if the stop key 12b is not pressed after printing (ST60-NO), the second sheet 11 is taken in and sample processing is performed according to the determined sample range. That is, the pickup motor 6a is turned on (ST
61), it is rotationally driven for 300 ms (ST62).

As a result, the leading edge of the sheet 11 hits the rollers 9a and 9b of the registration roller 9 and the sheet 1
A slack is formed at 1. In this state, the pickup motor 6a is stopped (ST63).

Next, the registration motor 6b is turned on (ST
64) Then, the registration roller 9 feeds the paper 11 to the printing unit (not shown). And the registration motor 6b
When the is turned on, the paper feed counter in the CPU 16 is cleared to "0" (ST65).

Then, when the count value of the paper feed counter reaches the sampling start value (ST66-YES), the point where the paper feed counter is cleared is set as the leading edge of the paper 11, and the sample range determined by the sample range determination operation is set. Sample processing in the paper transport direction is performed by the paper thickness detecting means 1 (ST6).
7-ST69). This sample processing is performed within the set sample range each time the registration roller 9 feeds the paper 11 by 1 mm and the encoder sensor 7 interrupts.

When the paper feed counter reaches the sample end value (ST70-YES), the sample data of the first sheet is compared with the sample data of this time, and it is confirmed and discriminated whether or not the two sheets are fed in layers (ST71). This sample data value is 1
When the amount of transmitted light is significantly smaller than the sample data value of the first sheet, it is determined that the sheets are fed in two layers. As a method of discriminating the double-sheet feeding by comparing sample data, a method of comparing average values of sample data of each paper, a method of selecting and comparing good sample data of each paper, sample data of each paper There is a method of comparing a plurality of points. In any case, since the sample data is obtained at a plurality of points along the sheet conveying direction, it is possible to discriminate the overlapped feeding through the entire sheet. Therefore, even if printing has already been performed on the back surface of the paper, there is less risk of misjudgment due to the deviation of the sampling position.

Note that ST61 to ST7 in the above operation
0 is the same processing content as ST47 to ST56.

When it is determined by the above-mentioned double-sheet overlap feed detection that the two-sheet overlap feed has occurred (ST71-YES), the two-sheet overlap feed warning lamp 14 on the operation panel 3 is turned on (ST72). As a result, the user is notified that two sheets have been fed, and printing is interrupted. After that, the registration motor 6b is turned off (ST73), and the initial state is restored.

On the other hand, if it is not determined that the sheet is fed by two sheets (ST71-NO), the sheet is conveyed by 60 mm and fed (ST74), the registration motor 6b is turned off (ST75), and the printing operation is started. (ST59). Then, printing is performed, and if the press of the stop key 12b is confirmed, if there is no press, paper feeding is repeated again. Stop key 12
If b is pressed, printing is terminated.

In the present embodiment, as a sheet storing means, the sheet feeding table 1 which is moved up and down by an elevator mechanism (not shown).
Although 9 is taken as an example, the present invention is not limited to this as long as the paper size in the transport direction can be detected, and other well-known materials such as a paper feed cassette may be used as the accommodating means.

(Third Embodiment) FIG. 13 is a block diagram showing a third embodiment of an overlapped feeding detection device relating to a sheet feeding device of a printing machine according to the present invention, and FIG. 14 is an operation panel of the third embodiment. FIG. The same components as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In the overlapped feeding detection device according to the paper feeding device of the printing machine of the third embodiment, the paper size key 12c and the paper size lamp 13 of the operation panel 3 in the configuration of the first embodiment are deleted, and 2 Unable to detect sheet stack feed lamp 2
In this configuration, 1 is added.

In the third embodiment, the signals of the paper thickness detecting means 11 are sampled at a plurality of positions in the carrying direction of the paper 11, and the paper size of the paper 11 in the carrying direction is calculated from this sample data. The double-sheet feeding detection impossible lamp 21 is turned on by a command from the microcomputer 4 when it is determined that the double-sheet feeding cannot be detected by the sample data based on the sheet thickness detecting means 1.

Next, the operation of the third embodiment will be described with reference to the flowcharts of FIGS.

In the third embodiment, the sheet size (sheet length in the carrying direction) is detected during sheet feeding, and the trailing edge of the sheet 11 passes the light receiving sensor 1b from the beginning of rotation of the registration roller 9. The sheet feed amount of the registration roller 9 until the above is set to the length in the transport direction of the sheet 11.

Further, the passage of the light receiving sensor 1b at the rear end of the paper 11 is made when the sample data value of the light receiving sensor 1b during feeding becomes 90% or more of the sample data value of the light receiving sensor 1b in the paper-free state. .

In the flowchart of FIG. 15, when the start key 12a is pressed (ST81-YES), the two-sheet overlap feed detection printing operation shown in FIGS. 16 to 18 is started (ST82).

In the double-sheet feeding detection printing operation, first, 2
If the single-sheet feeding warning lamp 14 and the double-sheet feeding undetectable lamp 21 are on, they are turned off (ST83, 8).
4). RA is the sample data obtained by the light receiving sensor 1b when the paper 11 is not passing through the conveyance path 10 between the light emitting sensor 1a and the light receiving sensor 1b, that is, when there is no paper.
It is stored and stored in M18 (ST85).

Next, the pickup motor 6a is turned on (ST86) and rotationally driven for 300 ms (ST8).
7). As a result, the leading edge of the sheet 11 hits between the rollers 9a and 9b of the registration roller 9, and the slack is formed on the sheet 11. In this state, the pickup motor 6a
Is stopped (ST88).

Next, the registration motor 6b is turned on (ST
89) Then, the registration roller 9 feeds the paper 11 to the printing unit (not shown). And the registration motor 6b
When the is turned on, the paper feed counter in the CPU 16 is cleared to "0" (ST90).

Then, the light receiving sensor 1 during conveyance of the paper 11
The sample data by b is stored in the RAM 18 (ST
91). After that, the count value of the paper feed counter in the CPU 16 is stored (ST92). When the registration roller 6b rotates, the paper 11 is conveyed by 1 mm, and when the interrupt signal is input from the encoder sensor 7, the count value of the paper feed counter is incremented by 1 (ST.
93).

Then, the sample data value by the light receiving sensor 1b is a reference value (sample data value in the absence of paper × 0.
9) When the above is reached and it is determined that the trailing edge of the paper is present (ST94-
YES), the length of the paper 11 is such that two sheets can be detected by feeding,
That is, it is determined whether or not it is smaller than 180 mm (ST9
5).

If it is determined that the length of the paper 11 is smaller than 180 mm (ST95-YES), the double-sheet feeding cannot be detected, so the double-sheet undetectable lamp 2
1 is turned on (ST96).

If the paper length is not shorter than 180 mm (ST95-NO), it is judged whether or not the paper 11 is shorter than 400 mm (ST97).

If the paper length is less than 400 mm (S
(T97-YES), the start of the sample range is determined to be 100 mm (ST98). Further, the end of the sample range is determined as a value obtained by subtracting 50 mm from the count value of the paper feed counter (ST99).

If the paper length is not less than 400 mm (ST97-NO), the sample range is 100 to 350 m.
m is determined (ST100).

The data determined by the above processing is 1
RAM1 as data of the sample range of the first sheet 11
The data is stored and stored in ST8 (ST101). Then paper 11
Is further conveyed by 60 mm (rear end 50 + margin 10 mm) and sent (ST102). Then, the registration motor 6b is turned off (ST103) and printing is performed (ST5).
9). This print transfer operation is the same as in the first embodiment and the second embodiment.
Since it is the same as the embodiment, the same reference numerals are given to the same processes,
The description is omitted.

Therefore, the first embodiment is provided with a paper size key for designating the size of the paper in the carrying direction.
The embodiment is equipped with a paper size determination sensor that detects the size of the paper in the transport direction, and the sample range is determined by the paper thickness detection means based on that information, so it is optimal for the paper size. A sample range can be obtained, and accurate overlap feed detection can be performed.

Further, in the third embodiment, during the transportation of the paper 11 within the set sample range, the paper thickness detecting means 1 samples at a plurality of positions in the transportation direction, and the paper 11 is transported from this sample data. The size of the direction is calculated, and the sample data in the range excluding the unstable area before and after the paper that is not suitable for the sample is used as the data for overlap feed detection. The detection can be automatically performed without the intervention of an operator, an optimum sample range according to the paper size can be obtained, and accurate overlapped feed detection can be performed.

By the way, in the third embodiment, when the first sheet 11 is fed, the sheet size in the carrying direction is detected, and the second sheet 11 to the first sheet 11 are detected.
Although the sheet size is detected according to the sheet size detected in step 1, the sheet size may be detected each time the sheet 11 is fed.

In the third embodiment, the two-sheet overlap feeding sample range is basically from the leading edge of the sheet of 100 mm to the trailing edge of the sheet of 50 mm. However, when the paper length is less than 180 mm, the sample range is too small, and therefore the operation is shifted to printing in which two sheets are not fed. Also, the paper length is 400 mm
In the above cases, the sample data memory capacity and CPU
The sample range is limited due to arithmetic processing. This idea is the same as that of the first and second embodiments described above.

In each of the above embodiments, the paper thickness detecting means is provided on the conveyance path between the pickup roller and the registration roller, but the present invention is not limited to this position. For example, if the sheet is provided in a stable state, that is, in the conveyance path to the printing unit that is conveyed in a flat state, it is possible to detect the overlapped feeding of the sheets with higher accuracy. Further, the number of paper thickness detecting means is not limited to one, but may be provided at a plurality of locations on the transport path.

In each of the above embodiments, the sample data of the sheet conveyed this time is compared with the sample data of the first sheet to detect the overlap feeding of the sheet 11, but
It is also possible to compare the sample data of the sheet that has been conveyed this time with the previously stored sample data that has been updated and detect the overlapped feeding of the sheet 11.

The paper thickness detecting means 1 is a light emitting sensor 1a.
Although the case where the transmission type optical sensor by the light receiving sensor 1b is used has been described as an example, other sensors may be used.
For example, when a reflection type sensor is used for the paper thickness detecting means 1, a reflection light type sensor in which a light emitting sensor and a light receiving sensor are arranged in parallel is provided above or below the conveyance path 10 and the paper conveyed on the conveyance path 10 is provided. Light is emitted from the light emitting sensor to 11, and the reflected light is detected by the light receiving sensor.

When an ultrasonic sensor is used for the paper thickness detecting means 1, ultrasonic sensor pairs are provided so as to sandwich the conveying path 10 and ultrasonic waves are emitted to the paper 11 conveyed on the conveying path 10. Then, the ultrasonic waves transmitted through the paper are detected.

When a contact type sensor is used as the paper thickness detecting means 1, one of a pair of rollers for nipping and conveying the paper 11 can be moved up and down, and rollers moving between the rollers according to the thickness of the paper conveyed. A sensor is provided to detect the amount of movement.

When a transmission type or reflection type optical sensor or an ultrasonic type sensor is used as the paper thickness detecting means 1, it is 1
It is premised that the output when a sheet of paper is being transported and the output when a plurality of sheets of paper are being transported have changed.

[0107]

As is apparent from the above description, according to the present invention, the pickup roller for separating and conveying the sheets stacked on the mounting table one by one, and the sheet for receiving the sheet sent from the pickup roller. , The paper feeding device of the printing machine is provided with a pair of registration rollers that feed the paper to the printing unit at a predetermined timing after the paper feeding is temporarily stopped and the paper is slackened. It is possible to determine the optimum detection range and detect the overlapped feeding of the papers at a position close to the paper transporting source with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a multi-feed detection device relating to a paper feeding device of a printing machine according to the present invention.

FIG. 2 is a diagram showing an operation panel according to the first embodiment.

FIG. 3 is a diagram showing an arrangement configuration of motors of a sheet feeding device of a printing machine according to the present invention.

FIG. 4 is a block diagram showing a second embodiment of a stack feeding detection device related to a paper feeding device of a printing machine according to the present invention.

FIG. 5 is a diagram showing an operation panel according to a second embodiment.

FIG. 6 is a diagram showing a configuration of a paper size detecting unit according to a second embodiment.

FIG. 7 is an operation flowchart of the first and second embodiments.

FIG. 8 is a flowchart of a paper size display switching operation according to the first embodiment.

FIG. 9 is a flowchart of a paper size determination operation of the paper tray of the second embodiment.

FIG. 10 is a flowchart of a sample range determination operation of the first and second embodiments.

FIG. 11 is a flowchart of a double-sheet feeding detection printing operation according to the first and second embodiments.

FIG. 12 is a flowchart of a double-sheet feeding detection printing operation according to the first and second embodiments.

FIG. 13 is a block diagram showing a third embodiment of the overlapped feeding detection device according to the paper feeding device of the printing machine according to the present invention.

FIG. 14 is a diagram showing an operation panel according to a third embodiment.

FIG. 15 is an operation flowchart of the third embodiment.

FIG. 16 is a flowchart of a double-sheet feeding detection printing operation according to the third embodiment.

FIG. 17 is a flowchart of a double-sheet feeding detection printing operation according to the third embodiment.

FIG. 18 is a flowchart of a double-sheet feeding detection printing operation according to the third embodiment.

FIG. 19 is a diagram showing a state in which a light transmission type detection sensor is installed in the paper feeding mechanism.

FIG. 20 is a diagram showing a state where a sheet is slackened by a registration roller at the beginning of sheet feeding in FIG. 19;

FIG. 21 is a diagram showing a state in which the paper is separated from the pickup roller at the end of the paper feeding in FIG. 19;

FIG. 22 is a timing chart of the sheet feeding mechanism according to the sheet size.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Paper thickness detecting means, 1a ... Light emitting sensor, 1b ... Light receiving sensor, 3 ... Operation panel, 8 ... Pickup roller, 9 ...
Registration rollers, 10 ... Transport path, 11 ... Paper, 16 ...
CPU (processing means), 19 ... paper feed table, 20 ... paper size determination sensor.

Continuation of the front page (56) Reference JP-A-9-142699 (JP, A) JP-A-63-82260 (JP, A) JP-A-7-300256 (JP, A) JP-A-63-315272 (JP , A) JP 5-229674 (JP, A) JP 6-72593 (JP, A) JP 61-192647 (JP, A) JP 5-43091 (JP, A) 1-115647 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65H 7/12 B65H 3/46 B65H 7/14

Claims (9)

(57) [Claims] 1. Sheets placed on a placing table are separated one by one.
Pick-up roller and the paper sent from the pick-up roller.
After stopping and temporarily stopping the conveyance and slackening the paper,
A pair of registration rollers that convey to the printing section side at the timing
A sheet feeding device of a printing machine including a pickup roller and the pair of registration rollers.
Between the above-mentioned sheets that have been loosened after being conveyed between
Output the same signal to the pickup roller and
The paper thickness detection means provided on the conveyance between the pair of registration rollers, the paper size detection means for detecting the paper size of the conveyed paper in the conveyance direction, and the paper size detected by the paper size detection means According to
Set the detection range excluding the leading edge and trailing edge of the paper ,
Printing comprising: a processing unit that determines whether or not the sheets are overlaid on the basis of sample data detected by the sheet thickness detection unit within the set detection range.
Feeder of the machine . 2. The printing machine according to claim 1, wherein the paper size detecting means outputs a signal corresponding to a paper size in a paper transport direction based on switching of a switch on the operation panel.
Paper feeder . 3. The printing machine according to claim 1, wherein the paper size detecting means is provided in a containing means for containing the paper to be conveyed, and outputs a signal according to the paper size of the accommodated paper in the conveying direction. Paper feeder . 4. The processing means determines the paper size in the transport direction based on the sample data detected by the paper thickness detection means, and changes the detection range of the paper thickness detection means according to the determined paper size. The paper feeder of the printing machine according to claim 1.
Place 5. The processing means includes sample data detected by the paper thickness detecting means in the detection range of the sheet conveyed this time, and the sample data in the detection range of the sheet conveyed before the sheet. 2. The sheet feeding device of a printing machine according to claim 1, wherein the presence or absence of the overlapped feeding of the sheets is determined by comparing with the sample data detected by the sheet thickness detecting means. 6. The paper feeding device for a printing press according to claim 1, wherein the paper thickness detecting means is a transmitted light type sensor. 7. The paper feeding device of a printing machine according to claim 1, wherein the paper thickness detecting means is a reflected light type sensor. 8. The paper feeding device of a printing machine according to claim 1, wherein the paper thickness detecting means is an ultrasonic sensor. 9. The paper feeding device of a printing machine according to claim 1, wherein the paper thickness detecting means is a contact type sensor.